1. Field of the Invention
The present invention relates to a communication controller, a base station controller and a communication system, and more particularly, to a communication controller that performs a connection control of roaming when a subscriber terminal moves from the home area to another area and a communication controller that performs a connection control of a subscriber terminal located in the home area or roaming area. The present invention is also concerned with a base station controller that performs a connection control of a roaming when the subscriber terminal moves from the home area to another area. Further, the present invention relates to a communication system that performs a connection control of roaming when the subscriber terminal moves from the home area to another area in WLL (Wireless Local Loop).
2. Description of the Related Art
Recently, attention has been drawn to a WLL system in which subscriber lines are implemented by wireless channels in the access system from a switch to subscriber terminals. Generally, the wireless system is utilized in an isolated island, desert or mountainous area with difficulty in laying cables. However, recently, the wireless system has been increasingly utilized in urban areas because it may reduce the construction period and cost.
FIG. 12 is a diagram of a basic structure of the WLL system. The WLL system is made up of a local exchange 40 in a public network 400, base station controllers (BSC) 101 and 102, base transceiver stations (BTS) 201 and 202, and subscriber terminals 301-303.
The subscriber terminal 301 includes a stationary telephone set 301b and a subscriber unit 301a connected thereto and involved in wireless communication. The subscriber terminals 302 and 303 have the same structure as described above.
The exchange 40 is connected to the BSCs 101 and 102. The BSC 101 is connected to the BTS 201, which is connected to the subscriber terminals 301 and 302 via radio channels. The BSC 102 is connected to the BTS 202, which is connected to the subscriber terminal 303 via a radio channel.
The BSC 101, BTS 201, and the subscriber terminals 301 and 302 are located in an area E10, and the BSC 102, BTS 202, and subscriber terminal 303 are located in an area E20.
The BSCs 101 and 102 accommodate a plurality of wireless base stations, and communicates with the exchange 40 in protocol exchange processing. The BTSs 201 and 202 communicate with the subscriber terminals 301-303 on the air using radio waves (wireless channels).
The interface between the exchange 40 and the BSCs 101 and 102 is, for example, V5.2 that is the ETS (European Telecommunication Standard) 300, 347. The air interface between the BTSs 201 and 202 and the subscriber terminals 301-303 is, for example, a connection making system that conforms to CDMA or PHS.
However, the conventional WLL system described above is on the condition that the stationary telephone sets are used even when the subscriber channels are wireless. Thus, for example, in a case where the user initially contracts a communication service in the area E10 (home area), when the user moves to another area E20 (roaming area) out of contract due to relocation, the user cannot receive the communication service.
In that case, it is necessary to rewrite subscriber data managed in the exchange 40 and the BSC 102 and to rewrite the telephone number in order to enable the user to receive the communication service in the area E20. As described above, the conventional WLL system does not consider connection control of roaming and takes a lot of trouble in rewriting. Thus, the conventional WLL system does not have good convenience.
When the subscriber terminal is used close to the boundary, the conventional WLL system allows the user to be connected to only the registered area although the user should be originally connected to the area in which the better radio condition for communication is available.
Taking the above into consideration, it is an object of the present invention to provide a communication controller that employs a connection control of roaming in WLL and provides communication services by efficiently making a connection even when the subscriber changes the area.
Another object of the present invention is to provide a base station controller that employs a connection control of roaming in WLL and provides communication services by efficiently making a connection even when the subscriber changes the area.
A further object of the present invention is to provide a communication system that employs a connection control of roaming in WLL and provides communication services by efficiently making a connection even when the subscriber changes the area.
The above objects of the present invention are achieved by a communication controller performing a connection control of roaming in which a subscriber terminal moves from a home area to a roaming area, said communication controller comprising: identification number management unit which manages a home area identification number assigned to the subscriber terminal in the home area and a roaming area identification number assigned thereto in the roaming area; and call connection processing unit which translates the home area identification number and the roaming area identification number into each other for call connection processing.
The above and other objects, features and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings which illustrate preferred embodiments of the present invention by way of example.